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1.
Diaphorina citri is a vector of the bacterial causative agent of Huanglongbing (HLB?=?Citrus greening), a severe disease affecting citrus crops. As there is no known control for HLB, manipulating insect behaviour through deployment of semiochemicals offers a promising opportunity for protecting citrus crops. The behavioural responses of D. citri to plant volatiles, and the identity of these plant volatiles were investigated. Volatiles were collected from host plants Murraya paniculata, Citrus sinensis, C. reshni, C. limettioides, Poncirus trifoliata, and from non-host plants Psidium guajava, Mangifera indica, Anacardium occidentale. In behavioural assays, female D. citri spent more time in the arms containing volatiles from either M. paniculata or C. sinensis compared to the control arms. When D. citri was exposed to volatiles collected from A. occidentale, they preferred the control arm. Volatiles emitted from the other studied plants did not influence the foraging behaviour of D. citri. Chemical analyses of volatile extracts from C. sinensis, M. paniculata, and A. occidentale revealed the presence of the terpenoids (E)-4,8-dimethylnona-1,3,7–triene (DMNT) and (E,E)-4,8,12-trimethyltrideca-1,3,7,11-tetraene (TMTT) in higher amounts in A. occidentale. In further behavioural bioassays, female D. citri spent less time in arms containing a synthetic blend of DMNT and TMTT compared to the control arms. Female D. citri also spent less time in arms containing the synthetic blend in combination with volatile extracts from either M. paniculata or C. sinensis compared to the control arms. Results suggest that higher release of the two terpenoids by A. occidentale make this species unattractive to D. citri, and that the terpenoids could be used in reducing colonisation of citrus plants and therefore HLB infection.  相似文献   

2.
The sex pheromones of many aphid species from the subfamily Aphididae comprise a mixture of the iridoids (cyclopentanoids) (1R,4aS,7S,7aR)-nepetalactol and (4aS,7S,7aR)-nepetalactone. In this paper, we investigate whether other chemicals, in addition to nepetalactol and nepetalactone, are released from Dysaphis plantaginea (rosy apple aphid) oviparae as part of their sex pheromone. Four compounds present in an air entrainment sample collected from D. plantaginea oviparae feeding on apple (Malus silvestris c.v. Braburn) elicited electrophysiological responses from male D. plantaginea. Active peaks were tentatively identified by gas chromatography (GC) coupled with mass spectrometry, with identification confirmed by peak enhancement with authentic compounds on GC columns of different polarities. The electroantennography-active chemicals were (1R,4aS,7S,7aR)-nepetalactol, (4aS,7S,7aR)-nepetalactone, (1S,2R,3S)-dolichodial, and phenylacetonitrile. (1S,2R,3S)-Dolichodial elicited a behavioral response from male D. plantaginea and naïve-mated female parasitoids, Aphidius ervi. This is the first report of electrophysiological and behavioral responses from any aphid morph to (1S,2R,3S)-dolichodial. Whether or not (1S,2R,3S)-dolichodial is a third component of the aphid sex pheromone is discussed.  相似文献   

3.
Coking coal of the same rank from different countries and fields may be distinguished in terms of use value by rating on the basis of seven technological and petrographic characteristics that determine the coke yield and properties: the ash content Ad; the total sulfur content Std; the yield of volatiles Vdaf; the plastic-layer thickness y; the vitrinite reflection coefficient Ro; the content of vitrinite-group macerals Vt; and the basicity index Bb. A range of values and a rating (on a scale from 1 to 10) are established for each of these parameters. Each rating corresponds to a particular score (from 0.1 to 1.0). Ranges of Ad, Std, Vt, and Bb are established for the whole metamorphic series, while ranges of Vdaf, y, and Ro are established for individual ranks and groups of ranks. Altogether, 105 coking coals from Ukraine, Russia, the United States, Australia, and Canada that are used at Ukrainian coke plants are investigated. The range of rating scores and their mean values are determined for individual coal ranks and groups. As an example, three bituminous coals from Ukraine, the United States, and Australia are compared by the proposed method. This method permits objective assessment of the technological value of coal within a single rank and the selection of the best purchase option.  相似文献   

4.
For 63 samples of Ukrainian, Russian, and imported coal, equations for predicting the gross calorific value Qsdaf on the basis of the following coal characteristics are developed: Wa, Oddaf, Qsaf, and Car. The error is within the standard tolerances (σ ≤ 0.3 MJ/kg). With sufficient accuracy, Qsdaf may be predicted from equations based on petrographic characteristics such as the vitrinite reflectance, the content of liptinitegroup minerals, and the sum of lean macerals (I + 2Sv/3). In these equations, the coefficients correspond to the heat of combustion of the vitrinite components at different metamorphic stages, the liptinite, and the lean macerals.  相似文献   

5.
The possibility of express determination of the characteristics V IR daf , Ro, IR, yIR, ΣLCIR, and A IR d used in the ranking of coal on the basis of IR spectroscopy is assessed for a specific example: Kuznetsk coals of different maceral composition and metamorphic development. The IR characteristics are compared with values obtained by standard methods (Vdaf, Ro, r, y, ΣLC, and Ad).  相似文献   

6.
Concentrations of calcium, iron, potassium, magnesium, phosphorus, zinc, copper, selenium and nickel were determined in the muscle tissue of seven species of fish (Plagioscion squamosissimus, Geophagus surinamensis, Prochilodus lacustres, Curimata sp., Schizodon dissimilis, Ageneiosus ucayalensis and Hypostomus plecostomus) collected from the lower course of the Itapecuru River in the state of Maranhão, Brazil. The samples were digested in a nitricperchloric solution and analyzed using an inductively coupled plasma atomic emission spectrometer, with the construction of specific calibration curves for each element. The highest concentrations of constituent minerals were found for phosphorus, potassium, nickel and magnesium (399.83, 144.60, 90.20 and 29.49 mg 100 g?1, respectively) in G. surinamensi, P. lacustres and Curimata sp. The lowest concentrations were found for copper, zinc, iron and selenium (0.12, 0.51, 1.05 and 8.31 mg 100 g?1, respectively) in Curimata sp., S. dissimilis, A. ucayalensis and P. squamosissimus. The concentrations of all minerals can be considered low and are below the maximum limit established by Brazilian legislation for the human ingestion of fish meat. A comparison of the seven species of fish investigated revealed no statistically significant differences regarding the concentrations of minerals, suggesting that size and different dietary habits do not exert an influence on absorption. The low concentrations of metals, such as Fe, Cu, Zn and Ni, may be related to the environmental conditions of the mouth of the river, which receives ocean inputs that produce particular tide cycles with a strong dispersion capacity, thereby diminishing residence time in the water column and reducing the availability of these metals to species of fish.  相似文献   

7.
The specific and equivalent conductivity of the diluted aqueous solutions of diallyammonium polyelectrolytes, initial monomers (N,N-diallylammonium trifluoroacetate, N,N-diallyl-N-methylammonium trifluoroacetate, N,N-diallyl-N,N-dimethylammonium chloride), and also potassium trifluoroacetate and trifluoroacetic acid solutions are studied. The limiting ionic mobility of diallylammonium cations and trifluoroacetate anion are found. The regularities of concentration changes in the equivalent conductance of polyelectolytes solutions are established. The degree of dissociation of diallyammonium polymers is shown to depend both on the counterion nature and on the amine structure.  相似文献   

8.
Termite colonies are almost always founded by a pair of winged dispersers, in spite of the high costs and low success rates inherent in independent colony foundation. The dispersal flights of imagoes from natal colonies are followed by mate search, mediated by sex-pairing pheromones. Here, we studied the chemistry of sex-pairing pheromones and the related aspects of mate search in winged imagoes of two facultatively parthenogenetic species, Embiratermes neotenicus and Silvestritermes minutus, and an additional species from the same subfamily, Silvestritermes heyeri. All three species are widespread in the Neotropics, including the rainforests of French Guiana. After the dispersal flight and spontaneous loss of wings, females expose their hypertrophied tergal glands situated under abdominal tergites VIII – X. The females are attractive to males and, upon direct contact, the two sexes form characteristic tandems. Chemical analyses indicated that the females secrete species-specific combinations of unbranched, unsaturated C12 primary alcohols from the tergal glands, (3Z,6Z,8E)-dodeca-3,6,8-trien-1-ol (approx. 200 pg per female) and (3Z)-dodec-3-enol (185 pg) in E. neotenicus, (3Z,6Z)-dodeca-3,6-dien-1-ol (3500 pg) in S. heyeri, and (3Z,6Z)-dodeca-3,6-dien-1-ol (300 pg) and (3Z)-dodec-3-enol (50 pg) in S. minutus. (3Z,6Z,8E)-Dodeca-3,6,8-trien-1-ol and (3Z,6Z)-dodeca-3,6-dien-1-ol act as major pheromone components in the respective species and mimic the function of female tergal gland extracts in electrophysiological and behavioral experiments. Biologically relevant amounts of the third compound, (3Z)-dodec-3-enol, elicited non-significant reactions in males of E. neotenicus and S. minutus, and slight synergistic effects in males of S. minutus when tested in combination with the major component.  相似文献   

9.
Here, we report the identification and synthesis of the sex pheromone of female Margarodes prieskaensis (Jakubski), and the attractiveness of the synthetic pheromone to males in field trapping tests. Volatile organic compounds were collected from virgin females using a sample enrichment probe (SEP). Analyses by gas chromatography coupled to mass spectrometry revealed the presence of only two constituents. By scaling up the SEP, sufficient of the major constituent was collected for 1H and 13C nuclear magnetic resonance (NMR) analyses and ancillary NMR techniques. The sex attractant was identified as (2R,4R,6R,8R)-2,4,6,8-tetramethylundecan-1-ol. The enantiomerically pure compound was synthesized from octadecyl (2R,4R,6R,8R)-2,4,6,8-tetramethylundecanoate, a minor component of the uropygial (preen) gland secretion of the domestic goose, Anser domesticus. Field trapping experiments, carried out in vineyards in the Northern Cape Province of South Africa, showed that the synthetic compound was as attractive to winged males of M. prieskaensis as virgin females. The second compound detected was identified as the corresponding acetate, but addition of this did not affect the attractiveness of the major component. We believe this to be the first identification of a sex attractant of the Margarodidae.  相似文献   

10.
Simple chromates(V) MCrO4 (M = Sc, Y, Gd, Er, or Yb) and chromate(V) vanadates Gd(CrO4) x (VO4)1 ? x have been synthesized by a solid-phase method. All compounds crystallize in the xenotime-type structure, space group I41/amd, Z = 4. The unit cell parameters have been calculated as follows: for GdCrO4, a = 7.209(5) Å, c = 6.318(4) Å; for ErCrO4, a = 7.088(2) Å, c = 6.231(1) Å; for YbCrO4, a = 7.034(1) Å, c = 6.205(2) Å; for YCrO4, a = 7.108(3) Å, c = 6.254(3) Å; and for ScCrO4, a = 7.012(2) Å, c = 6.188(2) Å. Symmetry D 2d , established for the CrO4 tetrahedron during the Rietveld structure refinement, is verified by IR spectroscopy. The MCrO4 simple chromates are paramagnets; their magnetic moments range from 1.7 to 8.1 μ B .  相似文献   

11.
Many uncommon non-methylene-interrupted fatty acids (NMI FA) are present in limpet gonads, but their biological properties remain unknown. To investigate new biological effects of naturally occurring NMI FA in eukaryotic cells, the biological activities of structurally analogous (4Z,15Z)-octadecadienoic acid (1), (9Z,20Z)-tricosadienoic acid (2), and (12Z,23Z)-hexacosadienoic acid (3) were examined by using a yeast-based drug-screening system using the Ca2+-sensitive mutant strain, Saccharomyces cerevisiae (zdsergpdrpdr3Δ). Among 13, 1 showed restored growth activity at a dose of 80 µg/disc in the mutant yeast strain. This phenotype suggests that 1 suppresses Ca2+-signaling of the mutant yeast through inhibition of glycogen synthase kinase-3β (GSK-3β) or calcineurin pathways or both. From this result, the inhibitory activity of 13 against GSK-3β was further determined. 13 showed potent inhibitory activity against GSK-3β with IC50 values ranging from 8.7 to 21.9 µM. Inhibition of GSK-3β reduces gene expression of the gluconeogenic key enzymes in liver, so we analyzed glucose production in rat hepatoma H4IIE cells to assess GSK-3β inhibitory activity of 13. Acid 1 inhibited glucose production at 25 µM in H4IIE cells. Our results would open up new possibilities for an anti-diabetic effect of 1 and might provide important insights into understanding the biological properties of naturally occurring NMI FA.  相似文献   

12.
Halyomorpha halys (Stål) (Pentatomidae), called the brown marmorated stink bug (BMSB), is a newly invasive species in the eastern USA that is rapidly spreading from the original point of establishment in Allentown, PA. In its native range, the BMSB is reportedly attracted to methyl (E,E,Z)-2,4,6-decatrienoate, the male-produced pheromone of another pentatomid common in eastern Asia, Plautia stali Scott. In North America, Thyanta spp. are the only pentatomids known to produce methyl 2,4,6-decatrienoate [the (E,Z,Z)-isomer] as part of their pheromones. Methyl 2,4,6-decatrienoates were field-tested in Maryland to monitor the spread of the BMSB and to explore the possibility that Thyanta spp. are an alternate host for parasitic tachinid flies that use stink bug pheromones as host-finding kairomones. Here we report the first captures of adult and nymph BMSBs in traps baited with methyl (E,E,Z)-2,4,6-decatrienoate in central Maryland and present data verifying that the tachinid, Euclytia flava (Townsend), exploits methyl (E,Z,Z)-2,4,6-decatrienoate as a kairomone. We also report the unexpected finding that various isomers of methyl 2,4,6-decatrienoate attract Acrosternum hilare (Say), although this bug apparently does not produce methyl decatrienoates. Other stink bugs and tachinids native to North America were also attracted to methyl 2,4,6-decatrienoates. These data indicate there are Heteroptera in North America in addition to Thyanta spp. that probably use methyl 2,4,6-decatrienoates as pheromones. The evidence that some pentatomids exploit the pheromones of other true bugs as kairomones to find food or to congregate as a passive defense against tachinid parasitism is discussed.  相似文献   

13.
The bearded weevil, Rhinostomus barbirostris (Coleoptera: Curculionidae: Dryophthorinae), attacks coconut trees, oil palms and other species of Arecaceae. Besides direct damage, R. barbirostris may be a vector of diseases in coconut and oil palms, such as stem bleeding (resinosis) and red ring disease. Currently, the only method to control this weevil is by visual observation of damage and removal of infected plants. Semiochemical-based trapping could improve the effectiveness of monitoring and management of R. barbirostris. In comparisons of volatiles released by R. barbirostris males and females by gas chromatography (GC) two male-specific compounds were observed. GC-mass spectrometry (MS) and GC-Fourier transform-infrared (FTIR) analyses of the natural compounds suggested these were diastereoisomers of 5-hydroxy-4-methylheptan-3-one, also known as sitophilure, a pheromone component of other dryophthorine species. Synthesis of the mixture of all four stereoisomers of sitophilure was performed in two steps, and the chemical structures were confirmed by comparing GC retention times and MS and FTIR spectra of natural and synthetic compounds. The absolute configurations of the two male-specific compounds were elucidated by enantioselective GC; the major component was the (4S,5R)-isomer, and the minor component (4S,5S)-sitophilure. In analyses by GC-electroantennography (EAG) the antennae of male and female R. barbirostris only responded to the (4S,5R)-isomer of the synthetic sitophilure. The stereoisomeric mixture of sitophilure was attractive to both sexes of R. barbirostris in laboratory experiments in the presence of sugar cane volatiles, and a similar result was obtained in a preliminary field trapping test.  相似文献   

14.
The tail gland of the red fox (Vulpes vulpes) secretes lipids containing volatile terpenes used in social communication. We have analysed lipids extracted from fur of the tail gland, body (flanks) and muzzle of foxes. GC–MS showed a novel group of iso-valerate and tiglate monoesters of alkane-1,2-diols (C18:0–22:0). There was also a larger group of Type II diesters in which a second, longer chain, fatty acid (FA) was attached to the free alcohol group. LC–MS showed the full range of diol diesters, mostly C36:0–50:0, with smaller amounts of the corresponding mono-unsaturated tiglate esters. An additional group of diesters with higher MW (C49:0–62:0) containing two long-chain FA was present in the lipids of body and muzzle fur. After saponification and GC–MS, 98 fatty acids were characterized as their methyl esters. Apart from the C5 FA, most were saturated n-, iso-, anteiso- or other methyl-branched FA (C12:0–28:0) whose structures were determined by a combination of their mass spectra and Kovats retention indices. Several FA have not previously been found in nature or in vertebrates. Thirty-four alkane-1,2-diols were found as their TMS derivatives, mostly n-, iso- or anteiso-isomers of C16:0–25:0. The tail gland had the greatest amount of wax esters, from a greater variety of FA and diols, but lacked the esters with two long-chain FA. These findings show that fox skin lipids comprise mono- and di-esters of alkane-1,2-diols, and exhibit enormous complexity due to the diversity of their constituent FA, diols and the many possible isomers of their esters.  相似文献   

15.
Derivatives of 2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropanecarboxylic acid (chrysanthemic acid) are classic natural pyrethroids discovered in pyrethrum plants and show insecticidal activity. Chrysanthemic acid, with two asymmetric carbons, has four possible stereoisomers, and most natural pyrethroids have the (1R,3R)-trans configuration. Interestingly, chrysanthemic acid–related structures are also found in insect sex pheromones; carboxylic esters of (1R,3R)-trans-(2,2-dimethyl-3-(2-methylprop-1-enyl)cyclopropyl)methanol (chrysanthemyl alcohol) have been reported from two mealybug species. In the present study, another ester of chrysanthemyl alcohol was discovered from the striped mealybug, Ferrisia virgata (Cockerell), as its pheromone. By means of gas chromatography–mass spectrometry, nuclear magnetic resonance spectrometry, and high-performance liquid chromatography analyses using a chiral stationary phase column and authentic standards, the pheromone was identified as (1S,3R)-(?)-cis-chrysanthemyl tiglate. The (1S,3R)-enantiomer strongly attracted adult males in a greenhouse trapping bioassay, whereas the other enantiomers showed only weak activity. The cis configuration of the chrysanthemic acid–related structure appears to be relatively scarce in nature, and this is the first example reported from arthropods.  相似文献   

16.
A recent study showed that a wingless parasitoid, Gelis agilis, exhibits a suite of ant-like traits that repels attack from wolf spiders. When agitated, G. agilis secreted 6-methyl-5-hepten-2-one (sulcatone), which a small number of ant species produce as an alarm/panic pheromone. Here, we tested four Gelis parasitoid species, occurring in the same food chain and microhabitats, for the presence of sulcatone and conducted two-species choice bioassays with wolf spiders to determine their degree of susceptibility to attack. All four Gelis species, including both winged and wingless species, produced sulcatone, whereas a closely related species, Acrolyta nens, and the more distantly related Cotesia glomerata, did not. In two-choice bioassays, spiders overwhelmingly rejected the wingless Gelis species, preferring A. nens and C. glomerata. However, spiders exhibited no preference for either A. nens or G. areator, both of which are winged. Wingless gelines exhibited several ant-like traits, perhaps accounting for the reluctance of spiders to attack them. On the other hand, despite producing sulcatone, the winged G. areator more closely resembles other winged cryptines like A. nens, making it harder for spiders to distinguish between these two species. C. glomerata was also preferred by spiders over A. nens, suggesting that other non-sulcatone producing cryptines nevertheless possess traits that make them less attractive as prey. Phylogenetic reconstruction of the Cryptinae reveals that G. hortensis and G. proximus are ‘sister’species, with G. agilis, and G.areator in particular evolving along more distant trajectories. We discuss the possibility that wingless Gelis species have evolved a suite of ant-like traits as a form, of mimicry to repel predators on the ground.  相似文献   

17.
Males of Acanthoscelides obtectus (Coleoptera: Chrysomelidae, Bruchinae) emit methyl (E,R)-2,4,5-tetradecatrienoate that attracts females for mating. This study identified further roles for this compound in the sexual behavior of A. obtectus. Earlier observations revealed that males touched females with their antennae while tandem-running with them and initiated mounting and copulation, whereas they showed no such behavior toward other males. A series of subsequent laboratory choice tests were set up to establish if certain cuticular compounds aid contact sex recognition in A. obtectus. Males chose virgin females over other males. The activity toward females could be eliminated by rinsing with hexane, but was regained by application of female extract onto previously rinsed females. Gas chromatographic (GC) comparison of hexane extracts revealed the presence of two male-specific compounds, methyl (E,R)-2,4,5-tetradecatrienoate and octadecanal, which were absent from the behaviorally active female samples. Of the two compounds, methyl (E,R)-2,4,5-tetradecatrienoate was found to be responsible for the inhibition of male sexual behavior, similar to that observed with crude male extracts applied to virgin females. Furthermore, males preferred virgin over mated females. GC analyses revealed the presence of methyl (E,R)-2,4,5-tetradecatrienoate in mated females in amounts sufficient to curtail mating attempts. It appears that methyl (E,R)-2,4,5-tetradecatrienoate, besides being a male-produced sex pheromone, acts as a male-recognition signal in A. obtectus. Males also transfer it onto females during mating, resulting in mated females being avoided by courting males.  相似文献   

18.
We measured the ultrasonic velocity, U, density, ρ, and viscosity, η in Isobutyric acid - water binary liquid mixtures over the entire composition range at temperatures ranging from 300.15 to 313.15 K under atmospheric pressure. The experimental data values were analyzed to determine, various acoustical parameters: adiabatic compressibility, β, acoustic impedance, Z, free length, Lf, free volume, Vf, molar volume, Vm, relaxation time, τ, absorption coefficient, α/f2, internal pressure, πi, Gibb’s free energy, ΔG, cohesive energy, CE, Wada’s constant, W, Rao’s constant, Rm and relative association, RA. The variation of these parameters versus the mixture composition was explained on the basis of the intermolecular interactions between the components of the mixture.  相似文献   

19.
Powders of cubic niobium nitride δ-NbN x with a particle size of below 20 μm were prepared by reactive diffusion at T = 1455?1475°C under nitrogen pressures of P 1(N2) = 0.1?3 MPa and P 2(N2) = 25 MPa. For these powders, the values of the stoichiometric coefficient x, lattice parameter a, and the superconducting transition temperature Tc were measured and the a(x), T c(x) and T c(a) functions were analyzed. The T c values were found to linearly grow with increasing a (decreasing structure imperfection). A maximum value of T c (15.8 K) corresponded to a maximum value of a (4.3934 Å). Maximain the a(x) and T c(x) curves were found to correspond to a slightly substoichiometric nitride with x = 0.98. Having synthesized cubic niobium nitrides with 0.892 < x < 1.062, we managed to measure the dependences of a and T c on x all over the almost entire homogeneity range for δ-NbN x . Our a(x) and T c(a) functions were found to reasonably agree with those previously reported for SHS-produced δ-NbN x powders.  相似文献   

20.

Background

Whole grain (WG) intake is associated with reduced risk of obesity, type 2 diabetes and cardiovascular disease, whereas type 2 diabetes increases the risk of cognitive decline and dementia. The purpose of this study was to investigate the effects of short-term intervention with WG rye on cognitive functions, mood and cardiometabolic risk markers in middle-aged test subjects.

Method

Rye-based breads were provided to 38 healthy test subjects (aged 52-70y) during three consecutive days in a crossover study design, using white wheat flour bread (WWB) as a reference. The rye-based bread consisted of a WG rye kernel/flour mixture (1:1 ratio) supplemented with resistant starch type 2 (RS2) (RB?+?RS2). The last bread portion was ingested at 2100 h, and cognitive function, mood and cardiometabolic risk markers were determined the following morning, 11???14 h post intake.

Results

In comparison to WWB, the RB?+?RS2 product increased ratings of mood parameters (valance, P?<?0.001; activation P?<?0.05). No differences were seen in the cognitive tests depending on intervention (P?>?0.05). RB?+?RS2 increased insulin sensitivity (P?<?0.05), fasting levels of gut hormones (PYY, P?<?0.05; GLP-2, P?<?0.01) and fasting concentrations of plasma acetate, butyrate and total SCFA (P?<?0.001). In contrast, fasting levels of IL???1β were decreased (P?<?0.05). Insulin sensitivity was positively correlated with working memory test performance (P?<?0.05).

Conclusions

This study display novel findings regarding effects of WG rye products on mood, and glucose and appetite regulation in middle-aged subjects, indicating anti-diabetic properties of WG rye. The beneficial effects are suggested to be mediated through gut fermentation of dietary fiber in the RB?+?RS2 product.

Trial registration

The study was retrospectively registered at ClinicalTrials.gov, register number NCT03275948. Registered September 8 2017.
  相似文献   

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